Next piece of 2017 driver puzzle will be Bottas

Valtteri Bottas will be the next piece of the 2017 driver puzzle to slot into place.

Authoritative media sources, including Auto Motor und Sport and Denmark's Ekstra Bladet, report that the Finn has definitely signed a new deal to stay at Williams.

Sources say the contract, for just one year rather than the two that Williams ideally wanted, will be announced ahead of the Mexican grand prix next week.

Bottas, whose new teammate will be the Canadian teenager Lance Stroll, had been linked with Renault but Auto Motor und Sport said engineers at the Enstone based team are actually pushing for Kevin Magnussen to be retained.

Force India also has a key vacancy for 2017 following Nico Hulkenberg's Renault switch, and the Mercedes-backed Pascal Wehrlein and Esteban Ocon are in the running.

"There are a few vacancies and we are negotiating with several teams," confirmed Mercedes' Toto Wolff.

He confirmed that Mercedes' role as a customer engine supplier will "play a role" in the outcome of the talks, adding: "I believe that both - Pascal and Esteban - deserve a place in formula one.

"So we will try to make them stay in formula one with an opportunity to develop."

Indeed, Wehrlein is believed to also be in the running at Haas, with team boss Gene Haas indicating in Austin that Esteban Gutierrez's future is not secure.

And at Force India, one surprising rumour is that Sauber's Felipe Nasr is a candidate.

Auto Motor und Sport said Nasr, whose Banco do Brasil sponsorship is currently at Sauber, has Bernie Ecclestone's blessing because he wants at least one Brazilian on the 2017 grid.

But Nasr played down the reports.

"There's nothing really. I have no connection with them," he told Portuguese language media in Austin.

"It's a very desirable seat, but what I'm saying is that I specifically did not speak to them."